The solution is to directly delete them from Trac’s SQLite backend. There are several type of comments: Plain ones and comments that describe a change to the ticket’s properties. I’ll deal with only the plain comments, but the methods I describe should also be applicable to the other kinds.

First things you should note down the ticket number and the comment number. The comment number appears in the URL of the permalink to it. It is the number that is pointed by an arrow in the screenshot above, it will be displayed when you hover over the circled link. Now in the shell, cd to the db directory of you trac installation and do:

sqlite3 trac.db "delete from ticket_change where ticket=<TICKET NUM> and field='comment' and oldvalue=<COMMENT NUM>"

For example for the ticket in the screenshot:

sqlite3 trac.db "delete from ticket_change where ticket=12 and field='comment' and oldvalue=3"

You can delete different kinds of tickets by using other values in the field column, such as keywords and summary. Another useful column is the author column.

The following Python functions allow you to build and read these 6 chars URL-safe timestamps:

import base64
import struct
import time
 
def build_timestamp():
    """
    Return a 6 chars url-safe timestamp
    """
    return base64.urlsafe_b64encode(struct.pack("!L",int(time.time())))[:-2]
 
def read_timestamp(t):
    """
    Convert a 6 chars url-safe timestamp back to time
    """
    return struct.unpack("!L",base64.urlsafe_b64decode(t+"=="))[0]

These functions work by translating the timestamp into a 4-byte binary form and then encoding it using a URL-safe version of Base64. And finally we strip the padding, which is neither URL-safe nor necessary (as we know the size of the encoded data).

The result looks something like this:

In [72]: build_timestamp()
Out[72]: 'S9sNOQ'

We got a timestamp in using only 6 URL-safe chars.

 synclient TapButton1=0

To disable the tapping permanently you should use the following to run the command at the start of every KDE session.

echo "synclient TapButton1=0" > ~/.kde/env/disable-tapping.sh

The first one is that one must export the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY or else you get a error message from the underlying boto library:

  File "//usr/lib64/python2.5/site-packages/boto/connection.py", line 148, in __init__
    self.hmac = hmac.new(self.aws_secret_access_key, digestmod=sha)
AttributeError: S3Connection instance has no attribute 'aws_secret_access_key'

The second thing to note is that is the way to specify buckets for duplicity. Instead of

s3://<bucket-name>/<prefix>

which is used by s3cmd (which is a great tool), it asks to specify it using

s3+http://<bucket-name>/<prefix>

Being aware of these points can save some time and frustration. In order to automate the backup process one can use cron. For example add the following to your crontab

AWS_ACCESS_KEY_ID="<your-key-id>"
AWS_SECRET_ACCESS_KEY="<your-secret-access-key>"
0 1 * * 0  duplicity --no-encryption <folder-to-backup> s3+http://<bucket-name>/<prefix> &>> ~/backups.log
AWS_ACCESS_KEY_ID=""
AWS_SECRET_ACCESS_KEY=""

I unset the environment variables, so it won’t leak to other cron jobs unnecessarily.

To block an ip or I’p range in ufw you should do

sudo ufw deny from 188.162.67.197/21

But here is the catch. Only the recent versions of ufw (which the version that comes with Ubuntu 8.04 isn’t one of them) support inserting new rules. When you add a rule it gets appended. So if you had a rule before that allows everyone to connect to your server on port 80, it also allows the IP range you’re trying to block, to connect to your machine.

As it’s impossible to foresee all the rules you might use, one has to resort to deleting all the rules he has to override, then re-add them so they will be after the rule that blocks the IP range. However I disliked the idea and looked for a simpler solution.

The easiest method I’ve found was to manully edit ufw’s configurations:

sudo vim /var/lib/ufw/user.rules

And then move the rule I’ve added, which looks like this:

### tuple ### deny any any 0.0.0.0/0 any 188.162.67.197/21
-A ufw-user-input -s 188.162.67.197/21 -j DROP

above any other rules in the configuration file.

Afterward, you’ll have to restart ufw so it will reload its configurations.

sudo ufw disable
sudo ufw enable

 \lyxframeend
                 {}\lyxframe{Outline}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

After comparing my document to example (working) beamer documents I’ve found out that you must have an EndFrame command after your last frame.Too bad it wasn’t documented anywhere I’ve found as this little thing drove me crazy.

I’ve decided to compare one of the working playlist files and the “empty” Amarok generated playlist. Two things were noticeable:

1. Amarok uses forward slashes, like in a Linux environment, and the working playlist used backward slashes.
2. The working playlist used relative paths without any prefix – directly beginning with the path. Amarok prefixed the relative paths with a dot-slash (./).

After noticing those things I’ve modified my Amarok generated playlist to look like the Windows generated one, and voila, it worked. I tried going through Amarok’s configuration dialogs to find some option controlling the format of generated m3u playlists, but couldn’t find any (I’m using Amarok 1.4.10). So with my newly found wits I’ve looked for a way to make using the playlists easier. I’ve came up with the following one-liner:

find -name "*.m3u" | xargs -I{} sed "s/^\.\///;s/\//\\\\/g" -i'' {}

The command should be run in the MUSIC directory of the Sansa Clip’s filesystem. It recursivey looks for m3u playlists and for each one strips any leading dot-slash and replaces forward slashes with backward ones. It can be used to easily convert all your playlists to the format understandable by Sansa Clip.

At first, I’ve tried to use the English dash and en-dash but result weren’t satisfactory. Both of them were too light and positioned too low to be used in an Hebrew text written in the Culmus fonts (see screenshot).

So finally, I’ve decided to write a simple macro to emulate a Kav-Mafrid for the David font.

\newcommand{\dd}{\lower0.17em\hbox{-\kern-0.13em-}}

The command works by kerning two Hebrew, Maqaf’s, together (with a slight overlap to adjust width), and lowering their position to the middle of the line.

In the following screensot the first line features the Frank Ruehl font and it\’s Maqaf and Kav-Mafrid. The second line featured the david font with a Maqaf and the missing Kav-Mafrid ligature. The third line features the David font with English dash and en-dash. The last line uses David with the regular Maqaf and the \dd{} macro.

Different dash examples

As it can be seen, the \dd{} macro does provide a good alternative for the Kav-Mafrid. However this solution isn’t perfect. One can improve the macro by detecting if the Kav-Mafrid ligature is present in the current font and if so, use it instead of the kerned one. This would enable one to use the macro and safely switch fonts, knowing he will always get the best Kav-Mafrid possible.

For sometime before letting go of the issue, I’ve tried to correct the direction of the label. It could have been fixed by marking the float as English text in LyX (I use it for editing Hebrew papers, as it makes editing multi-lingual texts easy), effectively adding \selectlanguage{english} before the \begin{algorithm} line. However, it resulted in display mess in LyX and some LaTeX errors when compiling (also it seemed LaTeX could complete the first pass).

Today, I’ve decided to tackle and solve the problem for a new paper I’m writing. After searching a bit for a way to override the Algorithm environment label, I’ve found a general way to override a float label in LaTeX:

\floatname{floatname}{floatlabel}

So for our case it would look like this:

\floatname{algorithm}{אלגוריתם}

You should put it in your LaTeX preamble (Documents->Settings in LyX). This neatly fixes the problem (see screenshot below).